The proposed research is intended to examine the mechanisms of lytic, latent, and transforming infections by oncogenic DNA viruses. We will continue a study of the way in which SV40 enhances the replication of adenovirus in monkey cells. In addition we will study the relationship of non-permissive infection and oncogenic transformation. The prime tool in these studies will be the electron microscope. Macromolecular microscopy and immunoelectron microscopy will be used to study the general problem of the interaction of infectious agents and cells.